Organophosphate compounds, in particular organic esters of substituted phosphoric acids, have been developed for use as chemical weapons. These compounds inhibit cholinesterases and disrupt the peripheral nervous system by preventing these enzymes from breaking down acetylcholine. Some organophosphate compounds are sufficiently potent that even brief exposure may be fatal.
Organophosphate anticholinesterase agents include tabun (Ethyl N,N-dimethylphosphoramidocyanidate, also referred to as GA), sarin (O-Isopropyl methylphosphonofluoridate, also referred to as GB), soman (O-Pinacolyl methylphosphonofluoridate, also referred to as GD), and VX (O-ethyl-S-[2(diisopropylamino)ethyl]methylphosphonothiolate). Tabun, sarin, and soman in particular are highly volatile and easily disseminated in vapor form. They are also readily absorbed through the lungs, eyes, skin, and intestinal tract.
Present treatments for organophosphate exposure include the administration of anticholinergic agents such as atropine and glycopyrrolate, as well as agents such as pralidoxime (2-PAM) that prevent the aging of AChE and that reverse muscle paralysis. Diazepam, a benzodiazepine, can also be administered to treat organophosphate exposure.
The present treatments for organophosphate exposure, however, do not completely treat the effects of such exposure, and in addition are associated with unwanted side effects. In view of this and of the threat posed by organophosphate agents, improved therapies for treating individuals exposed to such agents and for preventing the harm that these agents can cause are needed.